Furnace.



M. A. HOFFT.

FURNACE.

APPLICATION FILED MAY 16. 1917.

l fi5 fi3go Patented Feb. 5, 1918.

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FURNACE.

APPLICATION FILED MAY 16, 19M.

M. A. HOFFT.

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FURNACE.

Specification of Eetterslatent.

To all 'uikom it may concern:

Be it known that l, MAURICE A. Horrr, a citizen of the United States,residing at Indianapolis, in the county of Marion and State of Indiana,have invented a new and useful Furnace, of which the following is aspecification.

The object of my invention is to provide improvements in details ofconstruction in that type of smokeless furnaces wherein the fuel issupported upon downwardly and rearwardly inclined grate bars andupwardly swinging feeder fingers, and the ash is delivered to downwardlyand rearwardly swinging plates, whereby the durability of the apparatusis materially increased.

The accompanying drawings illustrate my invention.

Figure 1 is a perspective view of the interior of a furnace constructedin accordance with my invention, the setting being shown in partialsection; Fig. 2 is a perspective view of my improved form of grate bar;Fig. 3 a perspective view of one of the plates for embedment in thebridge wall to form a support for one of the ash plates; Fig. d a

perspective view of ne end of the bridge plate which supports the lowerends of the grate bars; Fig. 5 a vertical section lengthwise of thefurnace, the plane of. the section being distorted at one point in orderto show one of the feeder fingers in side elevation.

In the drawings, 10 indicates a downwardly and rearwardly inclined plateor shelf extending across the front of the furnace setting 11. A bridgeplate 12 is arranged in setting 11 so that its upper edge 13 will be insubstantial alinement with the shelf 10 and this bridge plate isprovided with. a forward surface 14:, the purpose of which will appear.At each end the bridge plate 12 is provided with a laterally extend. edfooting 15 designed to be embedded in the setting 11. Near-each end andat the middle, upon its rear face, the bridge plate'12 is pro vided withan upwardly extended hook or finger 16 which is spaced through the rearface of bridge plate 12, said hook forming a supporting pocket for thedownwardly extendedfinger 17 of an arm 18 which is designed to form asupport for the ash plates 19, and of which several will be provided.Each arm 18 is provided at its rear end with a vertical plate 20 and ahorizontal plate 21 ofsuch form that plate 20. may rest against theforward face of thebridge wall 22, while plate 21 is embedded in, saidbridge wall. Each arm 18 near plate 20 is provided in its upper surfacewith a downwardly and rearwardly inclined transverse groove or pocket23.

In the form shown in the drawings, there are two ash plates 19, each ofwhich is slotted at various points, a indicated at 24,

and each of which is provided at its rear corners with a trunnion pin 25adapted to seat in one of the grooves 23. n

Each ash plate is provided with a down- Patented Fell. d, ilidildo Vwardly ended arm27, the lower end of which has pivoted, at 28, anoperating linlr 29 which is extended upwardly and forwardly through theface plate 30 and formed in a common'manner to support the ash platenormally in the position shown in lines in Fig. 5. V

lln devices of. this general type, very considerable dificulty isexperienced with the grate bars because, owing to the changes intemperature, they become warped and broken. By forming the grate bar inthe manner now to be described, l have elinated to a very considerabledegree this (111%- culty. My improved form of grate bar is shown in Fig.2 comprises a foot plate all having at its under side a rabbet 4L2 whichwill rest upon the upper edge of the bridge plate 12 feed by thesurfaces 13 and 14's,

The footing plate 41 is carried at the lower end of a comparatively deepnarrow rib or plate 13, the upper edge of which carrles,

along its sides, a series of tapered separated The walls 17 are setinward y from the ends of wall 46 so as to leave shallow notches he atthe edes of this portion of the grate her. The w at are cected hytraerse walls 49 which are preferably of the harming Ml tl spaces 50 1na common manner.

bone type, and these walls are separted by At their upper ends walls 47are transversely thickened, as indicated at 51, corresponding to thelateral extension of the wall 46 beyond walls 47. The lower faces ofwalls 47 at their upper ends, as indicated at 52, are smooth and flat soas to lie loosely upon shelf 10. By this arrangement, the weight of thegrate bars and the applied load is taken by the bridge plate 12 andshelf 10; the downward thrust is taken by surface 14 of bridge plate 12,and the bars are individually capable of free expansion and contractionupon shelf 10. It will also be-noted that the deep plates 43 will liebeneath the hottest portion of the fire wall, the shallower walls 47connected 'by the herringbone cross bars 49 will lie beneath the lesshot portions of the fire w ll. I have found in practice that thispeculiar combination has resulted in a grate bar which has a verylonglife and retains its original, shape.

the plates 43, while the spaces resulting from the registry of thenotches 48 are only sufiiclent to permit free circulationof air withoutpermitting the unburned fuel to drop through. The spaces between theplates 43 are filled by pivoted feeder fingers 60, each of'whichisprovided at its lower end with oppositely projected trunnions 61 andalso provided with a downwardly extending operating arm 62. Thetrunnions 61 are deslgned for reception in grooves 45 of plates 43. Themain body of the finger comprises a pair of parallel side plates 63substantially triangular in elevation. vThese side plates are connectedat their upper edges bytransverse grate bars 64'which are spaced apartto form air passages 65, and at their rear ends are connected by anarc-shaped plate 66 which forms a closure for the space between the rearends of the plates 63 so' that, when a feeder finger is thrown upwardly,as shown in section in Fig. 5, to feed the partially burned fueldownwardly along the grate bars, the plate 66 cut cleanly through thebed of fuel and prevent that port1on of the bed of fuel lying upon the Iupper portion of the grate bars from sliding downwardly until after thefeeder finger has been returned to its normal position.

The operating arms 62 are connected to links 66 which are extendedforwardly through face plate 30 and attached to suitable operatinglevers. 67. The particular manner in which the feeder fingers are to beoperated forms no vention. v

I claim as my invention:

1. In a furnace, the combination of a plupart of my present intrunnions,a plurality of feeder fingers mounted in the spaces between the deepplates ofv the grate bars and having trunnions pivotally supported inthe notches of the grate bars, and means for swinging said feederfingers. e

2. In a furnace, thecombination of a plurality of grate bars each formedof a comparatively deep plate at its lower end and a pair of verticalwalls at its upper end connected bycross bars, said vertical walls beingconnected by a cross wall with the upper end of the plate and the platehaving notches in its upper edge to receive feeder fin er trunnions, andhaving at its lower en a.

transverse plate having a width exceeding the thickness of the deepplate, a plurality of feeder fingers mounted in the spaces between thedeep plates of the grate bars and having trunnions pivotally supportedin the notches of the grate bars, and means for swinging said feederfingers.

3. As an article of manufacture, a grate bar comprising a comparativelydeep verti-- calplate havmg a transverse notch in its upper edge, atransverse wall at the upper "end of said lplate and having a' lateralextent exceeding t e thickness of said plate, .a pair :of parallel wallsconnected to the transverse wall and spaced apart a distance such thatthe distance between their outer faces exceeds the thickness of theplate, and a plurality of spaced herringbone walls connecting saidparallel walls.

4. As an article-of manufacture, a grate bar comprising a comparativelydeep verti-. cal plate having a transverse notch in its upper edge andhaving a plurality of laterally projecting space wall at the upper endof said plate and having a lateral extent exceeding the thickness ofsaid plate and the lateral extent of the teeth, a pair of parallel wallsconnected to the transverse wall and spaced apart a distance such thatthe distance between their teeth, a transverse outer faces exceeds thethickness of-theplate,

such that the distance between their outer faces is less than thetransverse extentof the transverse wall, and a plurality of spacedherringbone walls connecting sa1d parallel walls.

6. As an article of manufacture, a grate bar comprising a comparativelydeep vertioal plate having a transverse notch in its outer faces is lessthan the transverse extent, of the transverse wall, and a plurality ofaaaaaa spaced herringbone walls connecting said parallel walls.

7. As an article of manufacture, a grate bar comprising a comparativelydeep vertical plate having a transverse notch in its upper edge, atransverse wallat the upper end of sald plate and having a'lateralextent exceeding the thiclmess of said plate, a pair of parallel wallsconnected to the transverse wall and spaced apart a distance such thatthe distance between their outer faces exceeds the thickness of theplate, and a plurality of spaced walls connecting said parallel walls. 7In witness whereof, I have hereunto set my hand at Indianapolis,Indiana, this 27th day of March, A. D. one thousand nine hundred andseventeen.

' MAURICE A. Horr'r.

